US3979829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for preparing a tooth stump for a crown
Assignee: BELL BUR Inc
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Filing: 1975-11-26
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Granted: 1976-09-14
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Expires: 1995-11-26
Abstract
Abstract A rotary cutting tool for the reception in a dental drill and use in preparing a tooth stump for the mounting of a tooth crown has a frustoconical cavity and a frustoconical lateral exterior surface. The exterior surface shape facilitates manipulation of the tool by the dentist and the interior shape is covered with abrasive matter that, in use of the tool, serves to shape both the top and the lateral surfaces of the tooth stump spike. At the base of the tool, an annular, abrasive coated surface is provided to shape the tooth stump and provide a ledge in those situations where the spike is to receive a full crown. Adjacent the annular surface, the lateral exterior surface may be coated with water repellent material that serves to protect adjacent teeth from damage and to also minimize gum damage when gum penetration occurs. Cooling of the work piece with water or other fluids is facilitated by the use of lateral wall passages which are inclined at the trailing edges for the contemplated rotational movement of the tool so that encountered water particles are deflected into the cavity and onto the work surface.
Inventors
- 👤 Albano Lemos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:31
CPC Classifications
A; A61; A61C; A61C3/00; A61C3/02; B; B28; B28D; B28D1/00; B28D1/02; B28D1/04; B28D1/041
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
152 words
A rotary cutting tool for use in preparing a tooth stump for the mounting of a tooth crown thereon, said tool comprising an elongated shaft adapted for reception in a power driven dental drill chuck and for rotation about its longitudinal axis, said shaft having opposite ends, a rigid body having an axis of symmetry and being fixed to the shaft in coaxial arrangement with the longitudinal axis at one of said ends, said body having a base end axially offset from said one of said ends, and joined top and lateral walls with interior surfaces that define a frustoconical interior cavity with an opening to the body exterior at said base end, said lateral wall having an annular exterior surface that surrounds said opening at said base end, and said body having abrasive matter secured to the interior surfaces of the top and lateral walls and to said annular exterior surface.
Claim 2
Dependent Claim
152 words
A rotary cutting tool for use in preparing a tooth stump for the mounting of a tooth crown thereon, said tool comprising an elongated shaft adapted for reception in a power driven dental drill chuck and for rotation about its longitudinal axis, said shaft having opposite ends, a rigid body having an axis of symmetry and being fixed to the shaft in coaxial arrangement with the longitudinal axis at one of said ends, said body having a base end axially offset from said one of said ends, and joined top and lateral walls with interior surfaces that define a frustoconical interior cavity with an opening to the body exterior at said base end, said lateral wall having an annular exterior surface that surrounds said opening at said base end, and said body having abrasive matter secured to the interior surfaces of the top and lateral walls and to said annular exterior surface.
Claim 3
Dependent Claim
30 words
A rotary cutting tool in accord with claim 1 wherein said lateral wall has a frustoconical exterior surface that extends between the top wall and base end of said body.
Claim 4
Dependent Claim
29 words
A rotary cutting tool in accord with claim 2 wherein said frustoconical exterior surface is inclined to the body axis of symmetry at an angle between 27° and 24°.
Claim 5
Dependent Claim
23 words
A rotary cutting tool in accord with claim 2 wherein said body has water repelling synthetic material adhering to said frustoconical exterior surface.
Claim 6
Dependent Claim
27 words
A rotary cutting tool in accord with claim 4 wherein said water repelling synthetic material is selected from the group consisting of polyfluoroethylene derivatives and methylsiloxane derivatives.
Claim 7
Dependent Claim
47 words
A rotary cutting tool in accord with claim 4 wherein said frustoconical exterior surface and said annular exterior surface merge along a circular edge, and wherein said body has a continuous coating of water repelling synthetic material adhering to said frustoconical exterior surface along said circular edge.
Claim 8
Dependent Claim
38 words
A rotary cutting tool in accord with claim 1 wherein said lateral wall has a plurality of circumferentially spaced passageways which interconnect the body cavity and body exterior between the top wall and base end of the body.
Claim 9
Dependent Claim
63 words
A rotary cutting tool in accord with claim 7 wherein said tool has a predetermined direction of rotation about the axis of symmetry during the use thereof, wherein each of said passageways has a trailing side edge wall surface that is inclined and arranged to deflect fluids which enter the passageway into said cavity when said tool is rotated in said predetermined direction.
Claim 10
Dependent Claim
77 words
A rotary cutting tool in accord with claim 1 wherein said lateral wall has a frustoconical exterior surface that extends between the top wall and base end of said body and is inclined to the body axis of symmetry at an angle between 17° and 24°, and wherein said lateral wall has a plurality of circumferentially spaced passageways which interconnect the body cavity and the body exterior between the top wall and base end of the body.
Claim 11
Dependent Claim
99 words
A rotary cutting tool in accord with claim 9 wherein said frustoconical exterior surface and said annular exterior surface merge along a circular edge, wherein said body has a continuous coating of water repelling synthetic material adhering to said frustoconical exterior surface along said circular edge, wherein said tool has a predetermined direction of rotation about the axis of symmetry during use, and wherein each of said passageways has a trailing side edge wall surface that is inclined and arranged to deflect fluids which enter the passageway into said cavity when said tool is rotated in said predetermined direction.
Claim 12
Dependent Claim
33 words
A rotary cutting tool in accord with claim 1 wherein said lateral wall has an exterior lateral surface wherein said body has water repelling synthetic polymeric material adhering to the exterior lateral surface.
Claim 13
Dependent Claim
92 words
A rotary cutting tool in accord with claim 11 wherein said lateral wall has a plurality of circumferentially spaced passageways which interconnect the body cavity and body exterior between the top wall and base end of the body, wherein said tool has a predetermined direction of rotation about the axis of symmetry during the use thereof, wherein each of said passageways has a trailing side edge wall surface that is inclined and arranged to deflect fluids which enter the passageway into said cavity when said tool is rotated in said predetermined direction.
Claim 14
Dependent Claim
218 words
The combination with a dental drill having a power driven chuck adapted to receive and rotate a dental cutting tool in a predetermined direction, of a rotary cutting tool comprising an elongated shaft received in said chuck for rotation about its longitudinal axis, said shaft having opposite ends, a rigid body having an axis of symmetry and being arranged coaxially with said longitudinal axis, said body having a top wall fixed to the shaft at one of said opposite ends and having a perimeter, and a lateral wall joined to said top wall along said perimeter and having a base end that is offset from said one of said opposite ends, said top wall and lateral wall having interior surfaces that define a frustoconical interior cavity with an opening to the body exterior at said base end, said lateral wall having an annular exterior surface that surrounds said opening at said base end, and a plurality of circumferentially spaced passageways which interconnect the body cavity and body exterior between said top wall and said base end, said drill having fluid conduit means having a fluid outlet aligned with the path of rotational movement of the spaced passageways to project fluid thereinto, and said body having abrasive matter covering said interior surfaces of said top wall and lateral wall.
Claim 15
Dependent Claim
218 words
The combination with a dental drill having a power driven chuck adapted to receive and rotate a dental cutting tool in a predetermined direction, of a rotary cutting tool comprising an elongated shaft received in said chuck for rotation about its longitudinal axis, said shaft having opposite ends, a rigid body having an axis of symmetry and being arranged coaxially with said longitudinal axis, said body having a top wall fixed to the shaft at one of said opposite ends and having a perimeter, and a lateral wall joined to said top wall along said perimeter and having a base end that is offset from said one of said opposite ends, said top wall and lateral wall having interior surfaces that define a frustoconical interior cavity with an opening to the body exterior at said base end, said lateral wall having an annular exterior surface that surrounds said opening at said base end, and a plurality of circumferentially spaced passageways which interconnect the body cavity and body exterior between said top wall and said base end, said drill having fluid conduit means having a fluid outlet aligned with the path of rotational movement of the spaced passageways to project fluid thereinto, and said body having abrasive matter covering said interior surfaces of said top wall and lateral wall.
Claim 16
Dependent Claim
90 words
The combination in accord with claim 13 wherein said lateral wall has a frustoconical exterior surface which is inclined to the body axis of symmetry at an angle between 17° and 24°, wherein each of said passageways defines an elongated slot having an logitudinal axis that falls in a plane common to the axis of symmetry and has an inclined trailing side edge wall surface arranged to deflect fluids projected into said passageways from the fluid outlet into said cavity when said tool is rotatably driven in said predetermined direction.
Claim 17
Dependent Claim
46 words
The combination in accord with claim 14 wherein said frustoconical exterior surface and said annular exterior surface merge along a circular edge, and wherein said body has a narrow continuous coating of water repelling synthetic material adhering to said frustoconical exterior surface along said circular edge.
References Cited (Backward Citations)
US1216683A
Cited
US2707329A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-14 | 1980-03-15 | 1980-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-14 | 1984-03-15 | 1984-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-14 | 1988-03-15 | 1988-09-14 | $7700.00 | Window Closed / Lapsed |